A male Ixodes ricinus tick (smaller) copulating with a female tick (larger)
Ixodid or hard ticks are ticks of the family Ixodae. Hard ticks are distinguished from Argasidae or soft ticks by their chitinous external shell.

Hard ticks may remain underneath the skin of a host for long periods of time. Most tick-born diseases are carried by hard ticks, although there are some exceptions, such as relapsing fever.

See also: Tick.